ModesDeco2 or ModesMixer2 with PiAware - anybody tried this successfully

[Triple7]

In reference to FR24, I just had a quick look and found a flybe flight, we know flybe's are not ADSB equipped (and therefore have to be Mlatted), and yet FR24 can determine the callsign and departure and destination airports from that - see attached.

Not in any way trying to be smart, we are all here to learn and try and fathom stuff out.

Tim

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[spotter.ssol]

Hum, that's  absolutely new for me.

As I said, I'm not an expert of Mode-S message specs.  But I do now that some data is only transmitted when requested by a ground station.

Maybe that's the point. Maybe the ground stations at my coutry are not yet compliant with this standard, so that's why I never saw them. I'll keep looking for the answer.

[Anmer]

Where are you located?  Not a precise position, but nearest airport?

In your FlightAware feed account, do you see the View Live Traffic option?

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[edgy]

Callsign is transmitted in Mode-S (DF20, DF21), as well as ADS-B (DF17).

If the plane has no Mode-S, then you can use ACARS data.

I assume the big data combiners have ACARS people??

[Anmer]

Thanks Edgy.

As far as I can tell, these are Mode-S messages.

[edgy]

I think some radars don't interrogate 20, and 21, and of course some transponders don't reply because they have no hookup to the fancy autopilot stuff. I guess if they have a callsign window, it must transmit that though (if they were interrogated).

[spotter.ssol]

In reference to FR24, I just had a quick look and found a flybe flight, we know flybe's are not ADSB equipped (and therefore have to be Mlatted), and yet FR24 can determine the callsign and departure and destination airports from that - see attached.

Not in any way trying to be smart, we are all here to learn and try and fathom stuff out.

Tim

In this specific example, we cannot take conclusions, because this aircraft position is not being calculated by FR24 server. If you look at the radar information, you see that his position is provided by a local station (T-EGLF46). Most probably it's being "mlated" locally (this is a whole other story, very interesting btw) and then uploaded to FR24 as an ADSB plot.
Now look at this sample I've take near my region:

The radar information says T-MLAT, wich indicates that his position is calculated by FR24 servers. There is "No callsign" label. An this is the standard over here for mlat aircraft.
Looking at their page at: http://www.flightradar24.com/how-it-works
"Data provided by the FAA is often missing aircraft registration information and aircraft tracked with MLAT in many cases are missing the callsign information."
I'll look for mlat aircraft over Europe and try to find any aircraft that fits the same case as mine.

[spotter.ssol]

Where are you located?  Not a precise position, but nearest airport?

In your FlightAware feed account, do you see the View Live Traffic option?

My receiver is located at SSOL, about 300km SE from SBSP (São Paulo),  160km SW from SBBH (Belo Horizonte).
Yes, I see the option, but why?

[edgy]

spotter, the only thing I can think of from your description, is that your mode-s radars don't interrogate aircraft for DF20, and DF21 replies.

Without ADS-B, these are the only two that have callsign in them.

The radars get altitude and squawk with DF4, DF5 and they probably are happy with that.

The DF20, DF21 have the same info as 4,5, but also includes a bunch of autopilot stuff. Your traffic control probably doesn't have any displays for that. You'd think they'd be upgraded to a nice European radar and display system by now :-) Even an Italian one, you couldn't go wrong :-)

Just don't get a USA one, as they probably have all sorts of spy gear in it :-)

[spotter.ssol]

It makes sense now. Everything is pointing on this direction. Thanks!

[edgy]

One option I forgot to mention, is that some ADS-B software don't process DF20,21 messages. It isn't programmed in. Thus, the radar is interrogating, and the aircraft are replying, but your software has no algorithm in it to process them.

They just depend on ADS-B to get the callsign.

I don't know if that's the case with your software, but something to investigate I guess.

[spotter.ssol]

I don't think that's the case. We have great coverage over my country by FR24 receivers, and AFAIK they're capable of decoding this types.